Occurrence of Antibiotic-Resistant Bacteria in Therapy Pools and Surrounding Surfaces.

The number of patients colonized with antibiotic-resistant bacteria is increasing in health care facilities. Because transmission of antibiotic-resistant bacteria is feared, there exist reports that the affected patients are frequently excluded from hydrotherapy, which is a non-invasive and beneficial treatment used for patients with different diseases. Data from the literature suggest that deficient water disinfection measures exist, which are not always sufficient to kill all released bacteria. If the pool water is not disinfected properly, it may also infect the bathers. Immunocompromised patients are particularly susceptible to be infected with (antibiotic-resistant) bacteria. In order to determine the distribution of antibiotic-resistant bacteria in the pool water treatment system and the pool environment and to estimate the associated transmission risk we analyzed samples from eleven health care facilities. Antibiotic-resistant bacteria were found in the water and surface samples collected. One hundred and two antibiotic-resistant isolates from water samples and 307 isolates from surrounding surfaces were obtained, respectively. The majority of the isolates belonged to non-fermenting Gram-negative rods, like Pseudomonas spp. Some isolates were resistant to a wide range of the tested antibiotics. The results indicate a relation between the number of isolates in water samples and the number of patients using the pools in combination with deficiencies in water treatment. In the pool environment the highest number of isolates was obtained from barefoot areas and floor cleaning equipment.

Cellular uptake of drug loaded spider silk particles.

Medical therapies are often accompanied by un-wanted side-effects or, even worse, targeted cells can develop drug resistance leading to an ineffective treatment. Therefore, drug delivery systems are under investigation to lower the risk thereof. Drug carriers should be biocompatible, biodegradable, nontoxic, non-immunogenic, and should show controllable drug loading and release properties. Previous studies qualified spider silk particles as drug delivery carriers, however, cellular uptake was only tested with unloaded spider silk particles. Here, the effect of drug loading on cellular uptake of previously established spider silk-based particles made of eADF4(C16), eADF4(C16)RGD, eADF4(C16)R8G and eADF4(κ16) was investigated. Fluorescently labelled polyethylenimine was used as a model substance for loading eADF4(C16), eADF4(C16)RGD or eADF4(C16)R8G particles, and fluorescently labelled ssDNA was used for loading eADF4(κ16) particles. Upon loading polyanionic eADF4(C16) and eADF4(C16)RGD particles with polycationic polyethylenimine the cellular uptake efficiency was increased, while the uptake of eADF4(C16)R8G and polycationic eADF4(κ16) particles was decreased upon substance loading. The latter could be circumvented by coating substance-loaded eADF4(κ16) particles with an additional layer of eADF4(κ16) (layer-by-layer coating). Further, it could be shown that eADF4(C16)RGD and eADF4(κ16) uptake was based on clathrin-mediated endocytosis, whereas macropinocytosis was more important in case of eADF4(C16) and eADF4(C16)R8G particle uptake. Finally, it was confirmed that drugs, such as doxorubicin, can be efficiently delivered into and released within cells when spider silk particles were used as a carrier.